This may be old news but.....I've just discovered that the Webra MC carb's throat OD is the same size as the ST 2300, meaning that it should just drop-in. For those fighting a rich midrange, this could be the answer. Not to mention, with the cheap prices on the ST, buy an MC carb, Perry or Webra external pump, and a Karl Mueller header and pipe of choice, could be quite a bargain pattern motor, particularly thru Intermediate. The only question is which MC, the 9mm or 12mm ID? The factory ST carb is 11mm ID. Too bad the MC won't fit the OS 160. OS does make an MC carb for the 140RX, but Great Planes won't import it, I suspect they wouldn't be able to sell as many EFI motors. I think it would fit the 160FX but you would have to drill the holes for the carb retaining screws and you'd only get one shot. Can anybody tell me how much more potent the OS 160 is than the ST 2300?

The ST *is* a "bargain pattern motor", but not for 2M, 5kg models. Just won't spin the props needed. When I was using the ST on Hanson EMC2's, I was putting 27% nitro in it, and still turned 17 x 10N's as a "max"....If you can turn rpm's, noise notwithstanding, then it can do the job.

The newest ST carbs have all the fixes that came about from all the learning in '97-98....info/history on my website.

The best ones now are running with the Perry pump, the VP-30, and a good pipe....but you still need to keep the r's up to stay in the torque band of the motor. It's more rpm than torque by design, I think.

Bob, I have a ST 2300 in a 1/4 scale GP Giles 202. The engine is driving me nuts and deadsticks are taking a toll on my plane! I am turning an 18-8 (ST reccomends this), am using an OS F plug with a bisson muffler with one port sealed. I checked out your web site and it seems like the barrel modification is more than one should have to do (last resort?) What about having the opening (cat eye) at about 45 degrees to the rear or pointing at the front engine mount hole? Also you said to richen the main needle slightly from the point where it just 2 cycles. That's richer than normal right? What do you think would happen if I sent it to Super Tigre and told them it won't run? Do you think they would replace the carb with one of the new ones? Thanks in advance for any help that you could give me. PS....great web site!
Steve

Forgot to mention that I am using Cool Power 15% synthetic.
Steve

Steve, if it's dying rich, blubbering when trying to advance throttle, it's that cam groove shape, or the low speed adjustment... In my experience rotating the spraybar only confused things...on mine, I set it to point straight down the venturi.

If it's dying lean, then it's a fuel supply issue, and you may want to drill out the inlet nipple, and make sure that passages within the carb aren't restricting somehow. Most folks I knew at the time were drilling the inlet to 5/64", I believe (can't recall exactly, sorry).

The OS F is the best plug, and the CP should work fine....if the cam groove on the carb is not Straight, and has that "dogleg" in it, then it's the old carb, and it DEFINITELY was the source of the richen-up-and-die coming up on throttle....ALWAYS.

Hello Dave,Well I have the fist batch and I drove me nut for years on end,became a very good glaider pilot. As my last hope on that engine, purchase a cline regulator and it havent gone dead stick and the lousy midrange is gone. So happy with the 2300 that bought another one. Is on a 72 inch sukhoi w/ a17/8 and it haul it around with a lot of authority. Also own a REVPRO with a os 1.60,hatori header and pipe cline regulator 18/10 apc. Imo the st has more guts than the os. Later

I ran the ST2300 on pattern planes for many years. Bob gave me a lot of help in the beginning getting the engine to run well. I never got the original carb to run properly, even with the modifications and ended up buying Perry carbs, which worked well for me. I would, however, disagree with Bob that this engine doesn't have enough power to haul around a 2 meter plane. My last two planes with ST2300's were both Hydeouts that were about 10 pounds, 12 ounces. Not light by any means, but the ST pulled them around with plenty of power to fly the Masters sequence. I used a 16.5x12 or a 17x10 standard and Cool Power 15%. But, I do think the EMC2 that Bob mentioned is a larger fuse, so maybe that makes a difference.

DaveR, I also noticed the MC carb fit the ST 2300 and I have been wanting to try it. But, I sold my last 2300 header to Bob Give it a try and let us know if it works. I never could get the Cline unit to work well with this. I did run a Perry pump, but my favaorite setup was just using a header tank and muffler pressure.

Emory.

Oh, by the way, I did try the standard Webra carb on the ST 2300 and could not get it to work well. Just too rich.

Emory

I guess what I *meant* to write was "I don't think the ST has what it needs for today's PROPS, and SEQUENCES, not to mention Airframe designs"....things are just power-eaters. The FAI is more demanding than ever, and there has to be much low-end torque to accelerate these big props.

Other than that - Emory's right....
(I did, however choose the OS 1.60 after the ST 2300....the performance of the two just cannot be compared...)

What is the recommended header pipe setup for running a header tank without a pump?

This is an interesting Engine Comparison Chart.


_________
Schpankme

I have run the ST2300 in both a pattern plane and a 25% CAP

The Cap I used a bisson muffler, Perry pump/carb setup. It would turn an 18x6 OK

Pattern setup Perry pump/carb, 15cc Mac's quitepipe, 15% Ritches Brew and it would spin 8400rpm w/17x10n


get a Perry pump and carb and dont worry about the rest... $35 pump $38 carb


I still have a ST2300 w/perry pump/carb and Karl Mueller wraparound header and Macs 15cc quitepipe if anyone is interested in it.
$250 even throw in a new 17x10n APC prop. Complete setup INCLUDES nose ring and thrust washer puller and Tru-Turn spinner adapter nut.

email me off line at [email protected]

Wayne Galligan

I was just browsing and noted the ST comments.
Not everyone has the same results with engines apparently.

Anyway - I am still plugging along on gasoline engines and MAY have finally stumbled onto a working pattern setup -
I have a Roto 25 -on Ed Skorpa pipe - this whole unit of engine /pipe batt etc is a bit ober 3 lbs or 1 lb over a glow engine of similar power I turn a 16x10 APC at 8310 and the engine is extremely smooth --smooth enough that I fly it in a 10lb 3 ounce Funtana 90 -
This setup is not yet optimised . I am going out again today -I did stick the latest performance numbers in the Gas engine column under Roto25 -if anyone cares.
One terrific aid , is that the ROTO records max rpm in the air which you can read with your tach after the flight -by simply pointing it at a little LED.
This has helped me sort out props.
As for glow engines
I have kicked the habit.